Production of motor fuel components



Dec. 2i, 194s.

S. H. MCALLISTER PRODUCTION OF MOTOR FUEL COMPONENTS Filed NOV. 18, 1944 sswwmua his AHOMMM Patented Dec. 21,v 1948 PRODUCTION OF MOTOR FUEL COMPONENTS Sumner H. McAllister, Lafayette, vCalif., assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware Application November 18, 1944, Serial No. 564,114

2 Claims.

This invention relates to the synthesis of hydrocarbons suitable for use in motor fuels from lower boiling olefin-containing hydrocarbon mixtures. It deals particularly with an improved process involving a succession of Vclosely co-operating steps whereby high yields of higher quality products especially adapted for use in aviation gasoline may be obtained in an efficient and economical manner. p

The invention is particularly advantageous in the treatment of hydrocarbon mixtures containing olens having four and ve carbon atoms per molecule such as occur in the products of thermal or catalytic cracking of petroleum or other suitable carbonaceous materials. However, the process is also applicable to other mixtures comprising tertiary olens of different molecular weights and the corresponding normal olens whether produced by cracking or in any other manner, such, for example, as by dehydrogenation of the corresponding parailins or by dehydration of alcohols, etc. v

Various methods of using such starting materials to prepare motor fuel components have been proposed andprocedures involving polymerization or alkylation with such oleflns have been carried out on a large scale. Thecommercially successfulmethods of polymerization heretofore used have depended upon the polymerization of individual olefns, particularly the conversion of isobutylene to di-isobutylene, a type of reaction which willbe referred to hereinafterl as copolymerization, or upon the interpolymerization, i. e., polymerization in which two different olens combine, of tertiary olens with the corresponding secondary olens. Olen mixtures have also been polymerized non-selectively by contact with catalysts such asphosphoric acid on a support to produce polymers of a highly heterogeneous composition which on hydrogenation yield a polymer gasoline much inferior in quality to those obtainable by the other described procedures.

It has now been foundthat the productsfobtained by interpolymerizing olens of different molecular weights and hydrogenating the resulting dimers have hitherto unsuspectedadvantages as motor fuel components. Thus, for example, by interpolymerizing tertiary amylenes with normal butylenes or isobutylene with normal amylenes, isononylenes may be obtained which on hydrogenation give products having rich mixture performance index numbers of I160 compared with an index number of only 14Dv for the iso-octane obtained by co-polymerization of isobutylene. |Ilhis difference corresponds, to an increased power output of about 14% for the isononane products. An important object of the present invention is to provide a process for producing desirable interpolymers of this type in maximum yield, particularly the maximum production of isononanes from C4 and Cs olenic fractions. Another object is to reduce the cost of production of alkylation and polymerization products useful as gasoline components. Still other objects and advantages of the new process will be apparent from the following more detailed description of the invention.

According to the invention, high yields of which quality gasoline components are produced from cracked or other similar unsaturated hydrocarbons by rst segregating at least two fractions of differ.- ent average molecular weights containing diierent tertiaryand normal olens, particularly. a butane-butylene fraction which may also contain lower boiling olelns and a pentane-amylene fraction which may contain higher boiling hydrocarbons. The separated fractions are then separately treated to substantially remove `tertiary olens from the corresponding normal olefins. This separation may advantageously be effected by selective absorption of the tertiaryy olens in a suitable solvent, preferably a solvent such as aqueous sulfuric or phosphoric acid or the like which is also an veffective polymerization catalyst. But, however the separation is carried out, polymerization is preferably avoided at this stage. Each lof the separated tertiary olelns, preferably in solution in the polymerizing solvent used to effect their separation, is contacted with the residual, mainly normal, olefin-containing hydrocarbonv fraction from the other tertiary olefin separation treatment and the mixtures are separately subjected to interpolymerization conditions. Thus isobutylene is selectively absorbed from a butane-butylene fraction in which it is present with normal butylenes and the absorption product is reacted with the residual amylenes from a. lpentane-amylene fraction which has been treated with sulfuric acid to selectively absorb tertiary amylenes and leave thenormal amylenes substantially unaffected and the tertiary'amylene absorption product is interpolymerized withfthe residual butylenes remaining after the uisobutylene absorption treatment. These interpolymerizations are carried out in `both cases so as to flavor the formation of isononylenes. These are hydrogenated while the remaining unreacted oleflns, `with or without any Yother l olen as isobutylene.

polymers formed, may be used for alkylation of isobutane and the alkylate blended with the iso.

amylenes since the reactivity of the latter islof the same order as that of isobutylene while normal amylenes polymerize much more vslowly than isobutylene so that a large excess may be maintained in the reacting mixture and the reaction thus made to go substantially 4to.interpolymcriza'.

The sameV tion between the different olens.

Tio-

4 for example, this may be regulated'by varying the acid concentration) or by control of the proportions of the reactants or by the use of different reaction temperatures and/or times or by suitable combinations of all of these factors. In both interpolymerizations, however, it is desirable to maintain a substantial mo;lecular excess of the iess--reactivenortn-al olen over the tertiary ole-k fin present therewith. Thus, in reacting an iso- 1butylene absorption product in sulfuric acid with i residual amylenes from a tertiary amylene exthree and preferably five to ten mols of amylene l per-fniolof absorbed isobutylene. In this step of "the'process sulfuric acid of about 65% to 75% con'cent-rationv is preferred and a temperature of considerations apply t"o.,interpolymerizations be'` tween the normal olens and n addition the products obtai-ned by vreacting normal amylenes y with normal butylenes are of a `much inferior acid'of about 60% to about 85%4 concentration is'particularlysuitable since such 'acidis also an eiective polymerization catalyst. 'When employing such` a solvent ajtemperaturefbetween about C. and about'lQ C. 'gis preferably maintained in Vthe absorber in order to avoid olen fo polymerization. AThe absorption is preferably carried out with thehydrocarbons in theliquid phase but it is feasible tov selectively absorbA the tertiary olens from the starting Afractions in the gaseous state. In operations 'in the liquid phase an vacid to hydrocarbonvolume ratio of about '-0.5 21'1to about 1.5:1 or higher and a' time of contact of about 5 minutes to r30 minutes'is usually suicient for the selective removal of" about 90% Yto 98% of the tertiary olefin-content of butane-butylene and pentane-amylene `^frjactions of petroleum cracking products containing from about' 12% to 35% of'branched `chain olefinfs. vSince there is a somewhat greater tendency 'for Vtertiary amylenes to polymerize than-'isobutylcna it is preferred to carry out the absorption of the former under somewhat milder conditions within `the foregoing ranges than those used for the iso'- butylene absorption step in order that prematurepolymer formation may be avoidedas oom'- pletely as possible.

For maximum production of nonylenes faceording tothe invention the proportions of there- 'actants and the reaction conditions, should be adi -`justed ,in accordance with the different reactivities of the olens, involved so as to favor inter- "polymerization of the tertiary olens with the different olefins with which they are reacted. Thustertiary amylenes' are appreciablymore reL- active and tend to polymerize fasterjthan'isobutylene and this factmust betaken into consideration in the polymerization steps of the proc'- ess. -TheA diierence in reactivity betweenthe nor mal butylenes 'and normal' amylenesY is not so great although the butylenes appear 4to polymerize'somewhat more'readily valthough not as fast These differences 1in-'polymerization -rates may be compensated yfor by-adjustments in the activity of the polymerization catalysts (with aqueous acid polymerizationcatalysts,

about 70?30. to about 110a C. is suitable with anaveragereaction time of about 20 to 60 minutes. For'the other polymerization step of the process, namely the reaction of absorbed tertiary amylenes, i; e. trimethyl ethylene .andfcr :unsymmetricaljv methyl'r ethyl ethylene,v with residual unabsorbed normal butylenes, somewhat more drasticpolymerization `conditions are ad'vaniza-f geous `but lower ratios yof ynormal olefin tiary olefin may be used, although a inolar'gatio of at least two to oneis vprefer-red also. Suitable conditions are, yfor examplathe use of four to eight mois of secondaryxbutyiones per r'nol` of' absorbed tertiary amylene `in sulfuric acid of aboutl60%rto 80% concentration at about 60 C.` to about 120 C. `and a polymerization time ofabout 5 toas() minutes. Within these. pre, ferredranges substantially equivalent results may be obtained by different combinations of condi@ tions, for examplegvby the use of lowerv acid con vcentrations at higher temperatures Lor vice versa, In all cases, however, it is' desirable tor choose reaction conditions which give the maximum yield' of desired -isononylenes since it u@been found that theseon'hydrogenation, yield isono nanes which have desirable power output.` Thus, thel-isononane fraction of 'the products offithefinvention has -a rich mixture performance index number of i60 compared withy an index number of iorrthe isooctanes producedby hydrogenation of'di--isobutylene and tested under the .same con ditions` v1'li-his is quite unexpected since the octane numb er vof the' isononanes is not outstanding bein-g, in fact-,"lowerrthan tha-tsof bissel-octane. fz-As are sult fthe processor the invention makes `itsieasible to markedlyincrease the Ipower output which `may be obtained in an internal combustion engine from agiven amount of Grand C5 hydrocarabons. Also sincetheisononane fraction of theprod uct has a higher richmixture index number than the ICB fraction which is :usually .obtainedas a ley-product in the-process, it is preferred 'to Scare gate-fthe latter `prior` to the hydrogenationstep Ofi-the process lof the invention and'to ieedthese octylenes to analkylation vunit, most prefere ably. along Awith the res-iduai VbastidenesY and amylenes from the polymerization-step of` the nrocess.- :In thezalkylation unit these oleiinsare reacted with an isoparainsueli as isobutane in the presence 0f `arsuitalfile catalyst, -orexanipla ,sulfuric ,acid, vhydrogen fluoride or chloride, and the resultinglhigh octane paramos maybe blended 'with thefisononaoes ,from the hydrogenation step to'obtain a substantially complete lconversion of the starting oleiins to gasoline boiling products which give excellentperformane, particularlyjin aviation service.

The4 characterand steps of the processor `the linventioirwill be' 'ampli'ed'by describing a typical operation in connection with the attached drawing which shows, diagrammatically, by the user of conventional figures in general side elevation, one suitable arrangement of equipment in which the objects of the invention may be accomplished. The units and connections shown in the drawing are not to any exact or relative scale and many. pieces of auxiliary equipment including temper# ature regulating means, measuring devices, valves,; etc., have been omitted since their location will,

be obvious to those skilled in the art.

In the drawing, line I represents a feed line for supplying olefin-containing hydrocarbonsy comprising tertiary and normal butanes, butylenes, pentanes and amylenes and higher an'd lower boiling components, for example, prod-v ucts of thermal and/or catalytic cracking of pe;- troleum oils or the like, from a source not shown', to a fractionating column 2 in which a fraction of hydrocarbons of four carbon atoms per molecule is taken off as a side stream by line 3 and conducted to a condenser and accumulator '74. Another side stream composed essentially of C5 hydrocarbons is Withdrawn by line 5 to condenser and accumulator 6 while higher boiling products are removed as bottoms by line 1 and components of less than four carbon atoms per molecule are taken off overhead by line 8. The separated butane-butylene fraction is fed by lines 9 and I0 into a circulating stream of sulfuric acid and C4 hydrocarbons in line I I. The resulting mixture is passed by pump I2 through line I3 to reactor I4 which may be a tank containing baflies or inert packing or other suitable device for promoting intimate contact of the acid with the hydrocarbon under conditions controlled, by means not shown, so as to promote selective absorption of isobutylene in the acid without substantial polymerization or absorption of normal butylenes. To this end a part of the emulsion is advantageously recirculated by line I5 for mixing with the feed in line II while the remainder, equivalent in amount to the feed introduced by line I0 is removed by line I6 to a separator I1 in which the mixture is allowed to stratify so as to separate the residual unabsorbed normal butylenes and normal and isobutanes from the absorption product of isobutylene in sulfuric acid. At the same time the separated pentane-amylene fraction from c ondenser and accumulator 6 is conducted by line I8 to a circulating stream of sulfuric acid and hydrocarbon flowing in the circuit formed by pump 20, line 2|, reactor 22 and return lines 23 and I9. The conditions in this system are adjusted so that tertiary amylenes are selectively absorbed and the absorption product and unreacted hydrocarbons are removed by line 24 and separated yin decantation vessel 25. The tertiary olefin absorption steps of the process shown in the drawing as carried out in single units may each be effected in a series of stages operated counter-currentlyA in order to obtain more efficient selective absorption.

The absorption product of isobutylene in sulfuric acid, preferably containing a molar excess of acid to olefin, advantageously 2 to 3 mols or more of acid per mol of absorbed isobutylene, from separator I1 is fed by line 26 to line 21 where it is admixed with a molecular excess of amylenes in the residual hydrocarbons from separator 25 which are introduced by line 28. The isobutylene absorption product and amylene-containing hydrocarbon are advantageously thoroughly admixed under non-polymerizing conditions, as by orice plates 29 or other suitable means, before being fed into a circulating stream of emulsified acid and hydrocarbon flowing under poiymerization conditions through pump 30, line 3I, time tank 32 and return line 33. By proper adjustment of the operating conditions, as previously indicated, the absorbed isobutylene is caused to react with the amylenes in the liquid phase to produce branched chain nonylenes and to minimize formation of di-isobutylene and co-polymers of the amylenes present. To insure the desired high ratio of normal amylenes to absorbed isobutylene, unreacted amylenes recovered in a later stage of the process may be recycled by line 19 to mix with the amylenes in line 28. The reacted emulsion is withdrawn by line 34 to separator 35 from which residual C5 hydrocarbons and polymer are removed byline 36 while the separated acid is taken off by line 31 and returned to line I9 for reuse in the absorption of tertiary amylenes. The tertiary amylene absorption product, also preferably containing a molecular excess of acid based on the olefin absorbed, is withdrawn from separator 25 by line 38 and fed to line 39 where it is contacted with residual butane-butylene in the liquid phase from separator I1 introduced by line 49. The absorption product and hydrocarbon are thoroughly emulsified under non-polymerizing conditions by mixing means 4I and are then fed into a circulating stream of reaction mixture under polymerization conditions flowing through pump 42, line 43, time tank 44 and return line 45. The reaction conditions in this unit may be some'. what less drastic than those used in reactor 32 and are such as favor the production of isononylenes of desirable chain structure from the absorbed tertiary amylenes and unabsorbed normal butylenes present. Production of tertiary amylene copolymers and of octylenes from the normal.

butylenes is minimized by carrying out the reac' tion with a substantial excess of butylenes based on the amylenes present which butylenes may be supplied in part as recycled butylenes introduced into line 40 by line 18 and by maintaining a temperature and acid concentration at which copolymerization of normal butylenes is not favored. The reacted mixture is withdrawn from'the reaction system by line 46 and fed to separator 41 from which residual butane-butylenes and ad- -mixed polymer is removed by line 48 while the separated acid is returned by line to the isobutylene absorption system. f

The polymerization products from the two reaction stages of the process may be separately distilled to separate unreacted hydrocarbons therefrom by feeding the products from line 48 to still 49 and the pentane-amylene containing polymer from line 36 to still 50. The unreacted butane-butylenes and pentane-amylenes are taken off overhead by lines 5I' and 52 respectively while the polymers recovered as bottom products by lines 53 and 54 are combined and fed by line 55 to fractionating column 56 for separation of the desired isononylenes from the co-polymers formed therewith. The Ca fraction produced by butylene co-polymerization is taken oif overhead by line 51 while the desired isononylenes are removed as a side stream by line 58 and the amylene co-polymers and higher boiling products are recovered as bottoms by line 59. The isononylenes are conducted by line 60 to a hydrogenation unit 6I in which they are reacted with hydrogen in the presence of any suitable type of hydrogenation catalyst such, for example, as reduced nickel or nickel oxide with or without supports such as siliceous carriers, etc. Less active catalysts such as oxides or suldes of chroaaneen;

inurn, molybdenum and tungsten, :particularly mixtures Vof :tungsten and nickel -suldes,may also lbe used. The temperature, pressure, time of contact and hydrogen to isononylene. ratios vary widely 'depending upon the .activity .of the .catalyst `used but may be .readily adjusted in Vany given case so as to :insure the production .ci a substantially .saturated is'ononane product Aof high ysuper-charged eng-ine performance.. In some cases it may be desirable Vto fractionate the bottom product of column `i9 to separate a C10 fraction which may valso be hydrogenated along with .for separately from .the isononylenessince the sodecylenes produced by co-polymerization of tertiary '.amylenes yield isodecanes having .good performance characteristics. The reacted hydrogenation mixture is Withdrawn by line 62 and the fexcess hydrogen separated in column 63 and return-ed to the .hydrogenaton unit .by line Gt together with additional yhydrogen supplied by f3.0

.The unreacted C4 :and C5 hydrocarbons recovered'tfrom the polymers will contain substantial amounts of olens which are recycled in: part to the polymerization stages by lines t8 and ."lS respectively while the remainder of these streams are preferably fed by lines 6-6 and 6'! to line 168 containing the polymers of eight orless carbon atoms-per molecule which are :fed :to an alkylation unit y69. suitable .type and may comprise one or more -reactors 4connected 4in series or parallel in which the C4, C55 and vC8 .olens maybe reactedwith isobutane or other suitable isoparal-n introduced by liner 1Q. The :alkylations with these dil'erent .15.1"

tion Via line 13 vfrom vnormal butane `Whichis Withdrawn by line M. vThe alkylation-products and nnreacted pentanes may be recovered as bottoms by line '15 and after fractionation, 'by means not shown, to remove any undesired high boiling components may lbe blended inlunitfl 59 Alkylation unit '69 may be of any 'fr :no1 percent basis:

l Butane-butylene fraction Isc-butylene 18 Normal butylenes 30 lsobutane 10 Normal butane 42 *Pentane-a'mylene fraction Tertiary .amylenes 25.5 Normalamylenes", 24.5 I sope'ntane 18 Normal pentane 32 Treatment of the butano-butylene fraction lWith twoniols of sulfuric acid, of 70% concentration, pe'nmol'oi isobutylene at 20 C. for an average tiine-oixcontact of '20 minutes, `extracts `93% v-of the isobutylene lalong with 6% of normal butyleneswhile similar extraction .of the .pentaneamylene fraction removes 85% Yof the 4tertiary aznylene togetherwith 5% of :the normal amylenes. The vresidual hydrocarbon .layers trom the absorption operations had the following :composition:`

Residual butane-butylene Isohutylene f 1.6 Normal .butylenes 34.6 Isobutane 12.3 Normal butane .51.5

Residual pentzme-amylene Tertiary amylenes .5.0 Normal amylenes .29.4 Iso'pentane' 23.6 Norma'lfpentanes 42;0

On reacting the absorption products with -the residual oleiinecontaining .hydrocarbon from ythe other absorption step of the process, the following results are obtained under the reaction conditions given below:

Reaction of absorbed Reaction of absorbed isobutylene with tertiary amylenes residual pentanewith residual buamylcnes tane-butylenes 'Mols of UnabsorbedfOlefin` per mol of absorbed Olefm 5/1 3/1 M01 ratio H2804 to total Olens 0.5/1 0.75/1 HzSO-i concentration l(hydrocarbon free bas1s) v i 70 70 Acid/HC. phase ratio .l/l lr/l Temperature, C. 80 90 f 'Average contact time l0 15 Y Per Gent Absorbed 'Tertiary Olen Reacted 100 90 Mol Ratio ofn-oleiinto Tertiary Olen v Reactecl 0.50/1 0.65/1 Gompositwn of polymer: Per -Cent Octylenes. 29 4 Per Cent Nonylenes.- 56 6l Per Cent Decylenes 5 `24 Per Cent higher boiling 10 ll l Composition of unreacted: f hydrocarbone: V

Butylenes 2 .Isobuty1enc 0 `Tertiary amylenes 2 Normal :buty- 26 l lanes. --Normal amylenes 17.5 Isobutane 13.5 lIsopentane. 28 'Normal butane 57.5 Normal pentane l50.5 Amylenes :3

"'9 On hydrogenation of the different polymer fractions using a nickel catalyst at '150 Grandl a liquid hourly space velocity of 2, paraflins having the following properties when tested in a one cylinder test engine as a 30% blend in a fuel containing 83% S and 17% Mand havingan F-3 rating equal to iso-octane +0.26 cc. TEL when containing 4.0 cc. TEL per gallon were obtained:

CRC F-4-443 (rich mixture anti-knock quality),

indem number Hydrogenated Products ci Reaction of Tertiary Amylenes With Residual Butane-Butylenes Hydrogenated Products of Reaction of Isobutylene with Residual Pentane-Amylenes C; fraction. Isononanes.. Cio !raction.

By feeding the residual unreacted olelns together with the Cs and C fractions of the polymer to an isobutane alkylation carried out in the presence of 90%-98% H2504 at 20 C. and using a feed ratio of isobutane to total olefin of 7:1 and an internal hydrocarbon recycle ratio of 20:1, the yield of aviation boiling products is 136% including an isononane yield of 39.5% based on the original olen fed. Furthermore, due to the pretreatment of the alkylation feed stock the alkylation catalyst life is exceptionally long being of the order of 20-30 volumes of alkylate per Volume of acid. This increase in acid life is achieved without any loss of valuable olens and the product made up of 30% isononanes, and 70% light alkylate has an octane number and a performance index number of 94 and 146, respectively.

It will be seen that the invention offers many advantages over prior methods of operation, particularly with respect to the yield of high quality motor fuel which it makes possible and the economy of operation achieved. It will be understood that; the invention is not restricted to the details of operation disclosed since many variations may be made in the procedure described. Thus, while reaction of absorbed tertiary oleiins with unabsorbed residual olen from the other separated fraction has been described I as the preferred procedure, it is possible to carry out the process in the reverse manner, as by reacting an absorption product of normal butylenes in surfuric acid, for example, with tertiary amylenes in an unabsorbed state and reacting an absorption product of the normal amylenes from which said tertiary amylenes were separated with isobutylene whether absorbed or not. The residual butylenes in line 40 of the drawing may be contacted with sulfuric acid to absorb secondary butylenes therefrom and the absorption product may be used in reactor 44 instead of the previously described mixture of butylenes and butane. The same modification may be used in the normal amylene reaction of the process. Alternatively, the tertiary olens may be separated by close fractionation or extractive or azeotropic distillation or absorption in a solvent and regeneration therefrom or other suitable manner and the reactions then carried out with the reactants in the liquid or vapor phase using a solid polymerization catalyst such, for example, as

phosphoric acid deposited on a-siliceous support or other suitable contact catalyst. Still other variations in the process may be made without departing from the principlesof the invention which isnot limited to the details disclosed by way of illustration nor by any theory proposed ,in explanation of the improved results achieved.

., carbon cracking products by fractionating -said cracking products to separate a fraction consisting of butanes, isobutylene and normal butylenes and another fraction consisting of pentanes, tertiary amylenes and normal amylenes, wherein isobutylene is selectively extracted from said butanebutylene fraction with aqueous sulfuric acid and tertiary amylene is selectively extracted from the pentane-amylene fraction, isononylenes are produced by separately reacting the isbutylene-containing extract with the residual hydrocarbon from said tertiary amylene extraction to effect interpolymerization of absorbed isobutylene with n-amylenes and reacting the tertiary amylenecontaining extract with residual hydrocarbon from said isobutylene extraction to effect interpolymerization of absorbed tertiary amylene with normal butylene, the hydrocarbon products of said interpolymerizations are separated from the acid present during said interpolyrnerizations, and the nonylenes produced are hydrogenated, the improvement which comprises feeding the acid separated from the hydrocarbon products of said isobutylene-n-amylenes interpolymerization to said tertiary amylene absorption and feeding the acid separated from the hydrocarbon products of said tertiary amylene-normal butylene interpolymerization to said isobutylene absorption.

2. In a process for producing nonylenes from a hydrocarbon fraction containing isobutylene and normal butylenes and another fraction containing tertiary amylenes and normal amylenes wherein isobutylene is selectively extracted from said isobutylene-containing fraction with a polymerization catalyst in the liquid phase under nonpolymerizing conditions, tertiary amylene is separately extracted selectively from said other fraction with a polymerization catalyst in the liquid phase under non-polymerizing conditions, the eX- tract of isobutylene in said liquid polymerization catalyst is reacted under polymerization conditions with the residual normal amylene-containing hydrocarbon from said tertiary amylene extraction to produce nonylenes, the extract of tertiary amylene in said liquid polymerization catalyst is separately reacted under polymerization conditions with residual normal butylene-containing hydrocarbon from said isobutylene extraction to produce nonylenes, and the polymerized mixtures are each separated into a polymercontaining hydrocarbon phase and a liquid polymerization catalyst phase, the improvement which comprises feeding the polymerization catalyst separated from the hydrocarbon products of said isobutylene-normal amylene interpolymerization to said tertiary amylene absorption and feeding the polymerization catalyst separated from the hydrocarbon products of said tertiary amylenenormal butylene interpolymerization to said isobutylene absorption.

SUMNER H. MCALLISTER.

(References on following page) Number- REFERENCES CITED 232,674 Thel following referencesl are of record in the 2,271,692 le of this patent: 2,300,315; UNITEU STATES PATENTS 5 2,342,074 2,353,490 Number Name Darte 1,844,211 Davis v Feb; 9, 1943 2,007,160 Engs -4-- JuIy 9', 15935 Number 2,138,881 Pyzel Dec. 6, 1938 `1'0 530,250 2,174,247 McAllister Sept. 26, 1939 Goldsby Aug. 13, 19'40 vName Date Y Pyzel Feb. 18, 1941 Perkins Jan. 27, 1942 Sweeney et a1- -,Nov. 3, 1942 Deanesly Feb. 15,1944 Noorduyn July 11,1944

FOREIGN PATENTS Country Date Great Britain Dec. 9, 1940 

